Metabolic effects of two regimens of growth hormone given before operation in piglets.
OBJECTIVE: To clarify the effects of growth hormone (GH) given three days before and at the start of a standard abdominal operation or at the start of the abdominal operation alone in piglets. DESIGN: Randomised experiment. SETTING: University hospital, Norway SUBJECTS: Twenty-four piglets. INTERVENTIONS: GH 24 IU was given intramuscularly for either three days before and on the morning of the operation or on the morning of a standard abdominal operation only (n = 8 in each group) A further 8 piglets acted as untreated controls. MAIN OUTCOME MEASURES: Diameter of fibres in the soleus and gastrocnemius muscles; urinary nitrogen excretion; and fat and carbohydrate oxidation measured by indirect calorimetry. RESULTS: Nitrogen excretion was reduced (in the three days group the mean (SEM) was 30.8 (4.2) mg/kg, corresponding figures from the one day group and the controls were 37.6 (5.8) and 55.4 (3.1) mg/kg, respectively, p = 0.004). Fat oxidation increased (for the whole period: p = 0.014) and carbohydrate oxidation decreased (p = 0.02) in the one day group only. The diameter of type I muscle fibres was increased in both muscles (soleus, three day group, mean (SEM) 37.5(1.4) microns compared with control, 30.4(0.6) microns, p = 0.001, and gastrocnemius, three day group 38.6(1.3) microns compared with control, 30.8(1.4) microns, p = 0.01). CONCLUSIONS: Three days treatment with GH enhanced nitrogen sparing and attenuated changes in fat and carbohydrate oxidation induced by one day treatment, but induced hypertrophy of type I muscle fibres.